Sebastian Mario Marcuccio

Palladium catalysed coupling of halobenzenes with arylboronic acids: Rôle of the triphenylphosphine ligand

Abstract The synthesis of unsymmetrically substituted biaryls via palladium catalysed coupling of aryl halides with arylboronic acids was found to produce biaryl by-products where one aryl was derived from the triphenylphosphine ligand. The use of substituted triphenylphosphine ligands to minimise this side reaction was investigated.

Modified Nucleosides. II.1 Economical Synthesis of 2′,3′-Dideoxycytidine

Abstract An economical two pot synthesis of 2′,3′-dideoxycytidine (2) from N4-acetyl-cytidine (4) has been developed. The key feature of this sequence is the in situ reductive elimination of a mixture of 1-(3-bromo-3-deoxy-2,5-di-O-acetyl-β-D-xylofuranosyl)-N4-acetylcytosine (5) and 1-(2-bromo-3-deoxy-3,5-di-O-acetyl-β-D-arabinofuranosyl)-N4-acetylcytosine (6) and subsequent hydrogenation of the resultant olefin over palladised charcoal.

A New Preparation of the Diastereoisomeric N-Acetylneuraminic Alditols

Acylation of the alditols (2) obtained by sodium borohydride reduction of N-acetylneuraminic acid (Neu5Ac) (1) gives a mixture of lactones (3) and (4) which can be separated and deprotected without epimerization yielding pure samples of the diastereoisomeric N-acetylneuraminic alditols (5) and (6).

Structural Reevaluation of the Crystalline Methylenedigallic Acids

Analysis of the products of the previously reported conditions for the preparation of crystalline methylenedigallic acids from gallic acid has revealed that the water-insoluble acid is a tetrahomodioxacalix[4]arene and the water-soluble acid is a trimeric species.